Self-contained cooler using dry ice refrigerant



Dec. 25, 1951 J. s. zUcKERMAN y 2,580,210

SELF-CONTAINED COOLER USING DRY ICEREFRIGERANT Filed Aug. 22. 1949 @H NH om Patented Dec. 25, 1951 Y REFRIGERANT Joseph vsi Zuckerman-omega nl. f Application ingest 2z, wiafs'eriai No; 111,637

Thisinve'ntion relatesV tot a.` oolerand particulariy to a cooler 'using Dry. Ice or simiiarmate- 'rial'. for use in portable units.- A.structureein'n bodyinglthe invention has numerous applications 'suoli as for 'example' in.. automobiles, trucks, freight cars and other vehicles" for transporting lhuman beings' and transporting freight requiring refrigeration. AA structure 'embodyin'gqth'e presentinvention mayaisoY be used', in homes,v and other plao'esjwriere a permanent-,installation is unnecessary'or uneconoinical, or where a. tem# poraryinstallationis required;` as in a sicklroom.

'Theiiiventioh contemplates a structure utilizing Dryfoe' `as 'the refrji'gerating` medium. ,A's is Well"`knWn,`Dry 1`ce is solid` carbon dioxide and sold in suchfo'r'm innumerous places.Y Dry Ice has."subs`tantial refrigeration possibilities. Howe'ver, its greatest drawb'aclhas-ben thai-,devices for utilizing DryIcev as a refrigerantY medium have not' vbeen "very, eiiicientdor Where efficiency hasbeen attained,I the apparatus lias'been complicated adiexpensive.

' Thisinventi'on contemplates a structure. which isjsimple and fool-prooi andi inwhclilthe refrigeration VpotentialDry Ice is .u'tlizec'lV in. an 'effective and' eiiicient manner. Vv(Jenti'arfy togm'ost prior art systems, .a structure yembodying the presentnvention 'does not require. .anysour'ceof' 'powerfoth'erithan `rthe' Dry c Ice. 'and' dispenses vwith the'.n'eces'sityforelectricity. y f i Y AY structure, embodying.y "the present invention 'in general has af container-'in' vvhich "Dryl Ice' is disposed and anfevaporator" 'through which gaseous carbonuioxidejinay pass. lvheevaporator is connected to theDryIce container so'that carbon'dioxidel evaporatingfV from' thje 'main body of Dry Ice" mayY pass' vthrough" theevaporator'. From the evaporator," a" pre'ssurereducing valve Vis provided toan exhaust. Connectedaoross 'the pressure reducing'valve'is 'aA gas vmotor orfturbine adapted: to driveffaian blowing air against' the evaporator. y'-Ih'us-thel drop-f in pressured-'carbon dioxide acrossrthef pressure'rreducing1valve'fisi utilized for obtaining a iiow. pf..aintpastorthrough the evaporator.

vA system embodying-the presentinvention'. has numerousl andimany;advantages.` First ofv all, `the systemi's simple and-:has few. parts.= `.Then the system is;l independent 'and selff-,containedfand requiresv no currentof electricity` for driving a fan. f The amount'lof refrigerationrobtained by -a unitembodying ftlliepresent invention is gener- 'ally proportionalto the load, this ofcourse being highly desirable:

Thus 'in-'f ai' system embodying lthe" presenty in- Aalso vhas means for eliminating-l condense'd Water or moisture'V atV the evaporatorV coils-,f1 Ysuch means for eliminationoeing simplefandffalso forming part of :the carbon dioxide dischargev path.

In order that-theinvention maybe understood, it will now be explained'fi'rr connection..withthe `drawings :wherein Figure; 1 shows` auf-ront" View of a simple unit embodying vthe present invention,

While-'Figure 2' shows a side View partlylinsection oftheunit shown iti-Figure 1l. l

' vThe unit embodyingfthe invention includes strage chambervlf-of vmetal'orvother suitable materialfin which Dry Ice" maybe'disposed in 'solidi form. 'Chamberle --is provided Withlcover 'I' lf'withl suitable: gasketfand clamping means for n'iaintaining-A the same 1ineposition-so--thatchamber I0 maybe sealed against'pressure developed in the storage chamber incident to the-'storage ofDryIce. Inasmuch as'press-ure resistant and gas-proof chambers of'j thisl type' are Well' known in 'pressure' cookers and other devices, aJ detailed 'description thereof Aappears-*toI be unnecessary.

vIn gen-eral, however, ychamber l0' maybe made Vof such materialasf'iron` or steel"y or aluminum anolmay beY provided `with' shelf I 2V off Wirejgau'ze within the chamber for "supporting apiece of Dry'Ice.| Q l Chamberjfll' hasibottom'l'll to" which is' attached top'header i5." Header 'l 5 maybe attachedto'the lbottom or any Jther'partoitheY chamber'in any desired fashion as by bolting thereto." Connected to header l5 is radiator 16 oi metal, such as'copper4 or. aluminum. Thev variousparts ofthe radiator are joined together by Vcooling fins IT of 'co'DDenaluminum orotlier materia1`.` The cooling fins .may beattached to vthe tubing any particular fashion, or if desired', tubing Vmay be used` having finsintegral therewith, 'all' this being'l'vve'lllknownv in the. .refrigeration and heat exchange art. Y

The bottoms o'fradiator tubes I6 are attached to Ilower header I8.-` Such` radiators with topa-nd bottom headers are commonly used inautomobiles and'in automobile heatersof. thehotwfater type.

` iet'ofpressurereducing or relief valve` [Shaving Header Ilisv connected by pipe "vlavtotheinmanual adjustment knob 20 thereon for determining the outlet pressure. Inasmuch as pressure reducing valves are known, a detailed description thereof is unnecessary. In general, however, any desired type of pressure reducing valve may be used. Pressure reducing valve I9 has outlet 22 connected to exhaust pipe 23. Disposed within exhaust pipe 23 near part 22 thereof is Venturi section 25.

Branching from pipe I8a is pipe 21 leading to Valve 28 whose outlet 29 communicates with gas motor 30. Gas motor 30 has shaft 3| carrying fan 32 disposed in proximity to cooling fins I1. The direction of rotation of fan 32 may be as desired to blow air either from the motor through the cooling unit or from the cooling unit through the fan to the motor. Gas motor 30 may be of any desired type operating with compressed gas and in the simplest form may comprise a turbine of any construction. Gas motor 30 has outlet 34 connected into exhaust pipe 23.

The cooling unit is normally positioned as shown in Figures 1 and 2 with radiator I6 generally-vertical. Bottom header I8 is provided with moisture collecting tray 36. Water due to condensation upon the evaporator surface may thus collect. Tray 36 is provided with outlet 31. The tray is preferably so mounted that liquid in the tray tends to empty through outlet 31. Outlet 31 has water discharge pipe 38 connected thereto' with outlet end 39 of this pipe connected to exhaust 23 in proximity to venturi 25. Any water in pipe 38 may go into exhaust pipe 23.

The operation of the cooler is as follows: Assume that a mass of Dry Ice is disposed in chamber I with cover II sealed in position. A certain amount ofY Dry Ice will evaporate from the surface of the solid mass of Dry Ice and the carbon dioxide will settledown through evaporator I6. The evapora-ted carbon dioxide will absorb heat in evaporator I6. When the pressure in the evaporator reaches or exceeds a certain value, valve I9'will permit gas to discharge into exhaust pipe 23. Thus valve I9 will function as a safety or relief valve.

Since gas motor 30 is connected directly across valve I9 it will have impressed thereon gas pressure substantially equal to the pressure existing across the pressure reducing valve. This will cause motor operation land rotation of fan 32 with a consequent generation of a blast of air or other material past the cooling coil. This results in load being applied to the evaporator.

It is eviden-t that the greater the pressure ,differential across valve I9, the faster will motor 3i) turn. The pressure differential across reducing valve I9 in general will be a function of the load on the unit. The discharge side of valve I9 will generally have a pressure somewhat above atmospheric pressure. The inlet side of pressure reducing valve I9, may vary over a .wide range of values depending upon the heat load and in practice may be of the order of five orten pounds per square inch. Thus gas motor 30 will travel at high speed or low speed dependrator is above freezing. vThus condensation o1 water or moisture will result in water dripping to tray 36. As water collects in this tray, aspiration at Venturi'section 25 will result'in water being drawn off.

If the Aparts remain in the relative position pas.

With the gas motor connected as shown, there K will be a tendency for the motor to function as a relief valve.

of pipe, motor and the like, it is possible to have warm carbon dioxide at exhaust header I8 with i just enough pressure to operate the gas motor and maintain relief valve I 9 closed. This type of operation may be provided for under normal load. With a heavier load, increased vaporization of carbon dioxide will increase the gas pressure at header I8. Thisuincreased gas pressure will .drive motor 30' faster and will also have a tendencyy to open relief valve I9 at intervalsor to maintain the valve open a certain amount for continuous'escape of'some gas, depending upon the type of valve used. y l

It is also possible to reverse the ice chamber and relief valve connections with respect to the radiator. Thus chamber I0 may be connected directly to lower header I8 while pipe I8a going to valve I9 may be connected to upper header I5. In this way the natural tendency for warm gas to rise in radiator I6 will be used. I'his would u make I5 the exhaust header and I8 the intake header. In general, chamber ID may have the bottom wallyuninsulated as far as heat is concerned so that vaporization' of Dry Ice will be promoted. The remaining walls may be heat insulated or not. Generally a film of gas will form around the Dry Ice so that the sides and top of chamber I0 do not function eiciently for cooling. In order to'prevent the formation of frost, it may be desirable to insulate the top and sides of chamber Ill. The bottom'of chamber I0 will preferably be located near the air stream generated by the fan so lthat frosting will not occur or be minimized.

' Gas motor I0 as a rule will not have much heat generated there., However in case the motor runs hot, a Ventilating shroud may be Aprovided so that motor heat is, carried away by a stream of air to exhaust 23. In fact, a second Venturi section may be provided in exhaust 23 for pulling air from around motor 30 and discharging the same outside of the room orcar being cooled.

Exhaust 23 may have a flexible rubber hose attached thereto so that spent carbon dioxide may be discharged outside of a car.

It may be desirable to move venturi 25 and pipe end 39( to` a place onexhaust 23 to the right of where pipe 34 comes in (Fig. 2). Thus motor operation will always result in Venturi action irrespective of the condition of valve I9.

What is claimed is:

l. A cooler for use with Dry Ice" or .the like comprisinga closed tank,` an evaporator having one end thereof connected to said tank, a relief valve connectedat theother end of saidlradiator and having anexhaust side, anfimpeller'for mov- ,ing fluid load past said evaporator, aV gas motor for driving said impeller; means for connecting said motor across two points in said system hav- -ing a wgaspressuredifferential, a drip.. tray for said evaporator, an outlet for said,drip tray, a ,Venturi Sectien diseases@ the. .exhaust ,Side 0f Thus by proper proportion of the entire gas motor bypass section including the size 1 the relief valve and a connection between said drip outlet and Venturi section whereby exhaust gas will aspirate water from said drip tray.

2. A cooler for use with Dry Ice or the like comprising a closed tank for Dry Ice, an evaporator having a plurality of pipes terminating in inlet and outlet headers, said evaporator being normally disposed so that said pipes extend vertically, a connection from said tank to one of said headers for supplying gaseous carbon dioxide to said header, a relief valve connected to the other header and adapted to exhaust into atmosphere, a fan for blowing air to be cooled against said evaporator, a gas motor for driving said fan and connections disposing said motor across said relief valve.

3. The system according to claim 2 wherein the motor bypass portion of the system is adapted to accommodate and discharge substantially all gas under normal load so that the relief valve need not open except under increased load.

4. The system according to claim 2 wherein a pipe at the exhaust side of the relief valve is provided, a Venturi section in said pipe, a drip tray for said radiator and a pipe connection between said venturi and drip tray whereby the exhaust gas will aspirate condensate from said drip tray.

5. A cooler for use with Dry Ice or the like comprising a closed tank for Dry Ice, an evaporator having a plurality of pipes in parallel with top and bottom headers, said evaporator normally having the pipes running vertically, means for supporting said tank above said evaporator. a connection from the bottom of said tank to one of said headers, an exhaust valve connected to the other header and exhausting `to atmosphere, a fan for moving air past said evaporator, a gas motor for driving said fan, connections disposing said motor across said relief valve, a drip tray for said evaporator, a pipe attached to the exhaust side of said valve, a Venturi section in said pipe and a drain pipe connecting said Venturi section and drip tray whereby exhaust gas may aspirate condensate from drip tray.

JOSEPH S. ZUCKERMAN.

REFERENCES CITED The following references are of record in the le of this patent: i

UNITED STATES PATENTS Number Name Date 1,917,865 Wood July 11, 1933 1,917,866 Wood July 11, 1933 2,034,139 Grayson Mar. 17, 1936 2,046,451 Grayson July 7, 1936 

